The present invention relates to a plug and a receptacle of a connector by which microstrip lines formed on separate printed circuit boards to constitute high-frequency circuits can electrically be connected to and, if necessary, disconnected from each other.
In circuits handling signals of an ultrahigh frequency band a circuit pattern which is formed on a printed circuit board has a microstrip line structure on account of impedance matching. Where it is necessary that circuits formed by microstrip lines be separately mounted on a plurality of printed circuit boards, it is customary in the art to mount coaxial connectors to the microstrip lines and interconnect the coaxial connectors by coaxial cables to interconnect the microstrip lines of the separate printed circuit boards.
Since the coaxial connector is bulky as well as expensive, a large space is required for interconnecting the printed circuit boards. This introduces difficulty in miniaturization of the entire device. In view of this, it is considered to employ a connector which permits electrically direct connection of printed circuit boards, but the connector of this type has a high impedance, which mismatches with the microstrip line. If such a connector is used with ultrahigh frequency circuits, then a reflection occurs in the connector, resulting in deterioration of the signal quality. In the case of directly interconnecting printed circuit boards, particularly close tolerances are needed for positioning them relative to each other, so that their connection may sometimes become difficult. To avoid this, it is necessary to increase the widths and lengths of signal contacts and ground contacts of the connector, but this increases the inductance of the connector, and hence augments the impedance mismatching.